Safety and efficacy of the OdonAssist inflatable device for assisted vaginal birth: the BESANCON ASSIST study.

BACKGROUND: The first feasibility study of the OdonAssist inflatable device for use in clinically indicated assisted vaginal birth reported a success rate of 48% with no significant safety concerns. Additional studies exploring the device performance in other clinical settings are warranted before definitive conclusions can be drawn about its safety and efficacy in current practice. OBJECTIVE: This study aimed to investigate the safety and efficacy of the OdonAssist before conducting a randomized controlled trial. STUDY DESIGN: This was an open-label, nonrandomized study of 104 women with a clinically indicated assisted vaginal birth using the OdonAssist at the Besancon University Hospital, France. Data, including those of a nested cohort group of women who had an assisted vaginal birth using vacuum or spatulas because a trained OdonAssist device operator was not available at the time of delivery, were collected. The primary outcome measure was the proportion of successful assisted vaginal births using the OdonAssist. Neonatal outcome data were reviewed at days 1 and 28, and maternal outcomes were investigated up to day 90. RESULTS: Between December 2019 and May 2021, 2191 pregnant women were approached, and 83% (1636/1973) of them consented to participate in the study. Among them, 10.7% (176/1636) required an assisted vaginal birth owing to a vertex presentation at +1 and below. The OdonAssist was used in 59% of births (104/176), and 41.1% (72/176) of the participants were included in the nested cohort group. The rate of successful assisted vaginal births using the OdonAssist was 88.5% (92/104). No emergency cesarean deliveries were performed in the OdonAssist group. There were no serious adverse maternal or neonatal reactions related to the use of the device. The rate of third- and fourth-degree perineal tears with the OdonAssist was 3.8% (4/104). The maternal perception ratings of the birth experience with the OdonAssist (collected on days 1, 7, and 28 using a 15-point scale) were high. In addition, the operators reported a positive perception of the device, with ease of use across the different steps of the procedure. One single technique was used for all vertex fetal head positions. CONCLUSION: The OdonAssist is a safe and effective alternative to other current devices for assisted vaginal births. The high acceptance rate (83%) among pregnant women and the high rate of successful assisted vaginal births using the OdonAssist confirm the feasibility of a future randomized controlled trial.

Closed- or open-glottis pushing for vaginal delivery: a planned secondary analysis of the TRAnexamic Acid for Preventing postpartum hemorrhage after vaginal delivery study.

BACKGROUND: The effect on obstetrical outcomes of closed- or open-glottis pushing is uncertain among both nulliparous and parous women. OBJECTIVE: This study aimed to assess the association between open- or closed-glottis pushing and mode of delivery after an attempted singleton vaginal birth at or near term. STUDY DESIGN: This was an ancillary planned cohort study of the TRAAP (TRAnexamic Acid for Preventing postpartum hemorrhage after vaginal delivery) randomized controlled trial, conducted in 15 French maternity units from 2015 to 2016 that enrolled women with an attempted singleton vaginal delivery after 35 weeks' gestation. After randomization, characteristics of labor and delivery were prospectively collected, with special attention to active second-stage pushing and a specific planned questionnaire completed immediately after birth by the attending care provider. The exposure was the mode of pushing, classified into 2 groups: closed- or open-glottis. The main endpoint was operative vaginal delivery. Secondary endpoints were items of maternal morbidity, including severe perineal laceration, episiotomy, postpartum hemorrhage, duration of the second stage of labor, and a composite severe neonatal morbidity outcome. We also assessed immediate maternal satisfaction, experience of delivery, and psychological status 2 months after delivery. The associations between mode of pushing and outcome were analyzed by multivariate logistic regression to control for confounding bias, with multilevel mixed-effects analysis, and a random intercept for center. RESULTS: Among 3041 women included in our main analysis, 2463 (81.0%) used closed-glottis pushing and 578 (19.0%) open-glottis pushing; their respective operative vaginal delivery rates were 19.1% (n=471; 95% confidence interval, 17.6-20.7) and 12.5% (n=72; 95% confidence interval, 9.9-15.4; P<.001). In an analysis stratified according to parity and after controlling for available confounders, the rate of operative vaginal delivery did not differ between the groups among nulliparous women: 28.7% (n=399) for the closed-glottis and 27.5% (n=64) for the open-glottis group (adjusted odds ratio, 0.93; 95% confidence interval, 0.65-1.33; P=.7). The operative vaginal delivery rate was significantly lower for women using open- compared with closed-glottis pushing in the parous population: 2.3% (n=8) for the open- and 6.7% (n=72) for the closed-glottis groups (adjusted odds ratio, 0.43; 95% confidence interval, 0.19-0.90; P=.03). Other maternal and neonatal outcomes did not differ between the 2 modes of pushing among either the nulliparous or parous groups. CONCLUSION: Among nulliparous women with singleton pregnancies at term, the risk of operative vaginal birth did not differ according to mode of pushing. These results will inform shared decision-making about the mode of pushing during the second stage of labor.

Assisted vaginal birth in 21st century: current practice and new innovations.

Assisted vaginal birth rates are falling globally with rising cesarean delivery rates. Cesarean delivery is not without consequence, particularly when carried out in the second stage of labor. Cesarean delivery in the second stage is not entirely protective against pelvic floor morbidity and can lead to serious complications in a subsequent pregnancy. It should be acknowledged that the likelihood of morbidity for mother and baby associated with cesarean delivery increases with advancing labor and is greater than spontaneous vaginal birth, irrespective of the method of operative birth in the second stage of labor. In this article, we argue that assisted vaginal birth is a skilled and safe option that should always be considered and be available as an option for women who need assistance in the second stage of labor. Selecting the most appropriate mode of birth at full dilatation requires accurate clinical assessment, supported decision-making, and personalized care with consideration for the woman's preferences. Achieving vaginal birth with the primary instrument is more likely with forceps than with vacuum extraction (risk ratio, 0.58; 95% confidence interval, 0.39-0.88). Midcavity forceps are associated with a greater incidence of obstetric anal sphincter injury (odds ratio, 1.83; 95% confidence interval, 1.32-2.55) but no difference in neonatal Apgar score or umbilical artery pH. The risk for adverse outcomes is minimized when the procedure is conducted by a skilled accoucheur who selects the most appropriate instrument likely to achieve vaginal birth with the primary instrument. Anticipation of potential complications and dynamic decision-making are just as important as the technique for safe instrument use. Good communication with the woman and the birthing partner is vital and there are various recommendations on how to achieve this. There have been recent developments (such as OdonAssist) in device innovation, training, and strategies for implementation at a scale that can provide opportunities for both improved outcomes and reinvigoration of an essential skill that can save mothers' and babies' lives across the world.

The OdonAssist inflatable device for assisted vaginal birth-the ASSIST II study (United Kingdom).

BACKGROUND: Decreasing rates of assisted vaginal birth have been paralleled with increasing rates of cesarean deliveries over the last 40 years. The OdonAssist is a novel device for assisted vaginal birth. Iterative changes to clinical parameters, device design, and technique have been made to improve device efficacy and usability. OBJECTIVE: This study aimed to determine if the feasibility, safety, and efficacy of the OdonAssist device were sufficient to justify conducting a future randomized controlled trial. STUDY DESIGN: An open-label nonrandomized study of 104 participants having a clinically indicated assisted vaginal birth using the OdonAssist was undertaken at Southmead Hospital, Bristol, United Kingdom. Data were also collected from participants who consented to participate in the study but for whom trained OdonAssist operators were not available, providing a nested cohort. The primary clinical outcome was the proportion of births successfully expedited with the OdonAssist. Secondary outcomes included clinical, patient-reported, operator-reported, device and health care utilization. Neonatal outcome data were reviewed at day 28, and maternal outcomes were investigated up to day 90. Given that the number of successful OdonAssist births was ≥61 out of 104, the hypothesis of a poor rate of 50% was rejected in favor of a good rate of ≥65%. RESULTS: Between August 2019 and June 2021, 941 (64%) of the 1471 approached, eligible participants consented to participate. Of these, 104 received the OdonAssist intervention. Birth was assisted in all cephalic vertex fetal positions, at all stations ≥1 cm below the ischial spines (with or without regional analgesia). The OdonAssist was effective in 69 of the 104 (66%) cases, consistent with the hypothesis of a good efficacy rate. There were no serious device-related maternal or neonatal adverse reactions, and there were no serious adverse device effects. Only 4% of neonatal soft tissue bruising in the successful OdonAssist group was considered device-related, as opposed to 20% and 23% in the unsuccessful OdonAssist group and the nested cohort, respectively. Participants reported high birth perception scores. All practitioners found the device use to be straightforward. CONCLUSION: Recruitment to an interventional study of a new device for assisted vaginal birth is feasible; 64% of eligible participants were willing to participate. The success rate of the OdonAssist was comparable to that of the Kiwi OmniCup when introduced in the same unit in 2002, meeting the threshold for a randomized controlled trial to compare the OdonAssist with current standard practice. There were no disadvantages of study participation in terms of maternal and neonatal outcomes. There were potential advantages of using the OdonAssist, particularly reduced neonatal soft tissue injury. The same application technique is used for all fetal positions, with all operators deeming the device straightforward to use. This study provides important data to inform future study design.

Water birth: a systematic review and meta-analysis of maternal and neonatal outcomes.

OBJECTIVE: This systematic review and meta-analysis aimed to conduct a thorough and contemporary assessment of maternal and neonatal outcomes associated with water birth in comparison with land-based birth. DATA SOURCES: We conducted a comprehensive search of PubMed, EMBASE, CINAHL, and gray literature sources, from inception to February 28, 2023. STUDY ELIGIBILITY CRITERIA: We included randomized and nonrandomized studies that assessed maternal and neonatal outcomes in patients who delivered either conventionally or while submerged in water. METHODS: Pooled unadjusted odds ratios with 95% confidence intervals were calculated using a random-effects model (restricted maximum likelihood method). We assessed the 95% prediction intervals to estimate the likely range of future study results. To evaluate the robustness of the results, we calculated fragility indices. Maternal infection was designated as the primary outcome, whereas postpartum hemorrhage, perineal lacerations, obstetrical anal sphincter injury, umbilical cord avulsion, low Apgar scores, neonatal aspiration requiring resuscitation, neonatal infection, neonatal mortality within 30 days of birth, and neonatal intensive care unit admission were considered secondary outcomes. RESULTS: Of the 20,642 articles identified, 52 were included in the meta-analyses. Based on data from observational studies, water birth was not associated with increased probability of maternal infection compared with land birth (10 articles, 113,395 pregnancies; odds ratio, 0.93; 95% confidence interval, 0.76-1.14). Patients undergoing water birth had decreased odds of postpartum hemorrhage (21 articles, 149,732 pregnancies; odds ratio, 0.80; 95% confidence interval, 0.68-0.94). Neonates delivered while submerged in water had increased odds of cord avulsion (10 articles, 91,504 pregnancies; odds ratio, 1.75; 95% confidence interval, 1.38-2.24) and decreased odds of low Apgar scores (21 articles, 165,917 pregnancies; odds ratio, 0.69; 95% confidence interval, 0.58-0.82), neonatal infection (15 articles, 53,635 pregnancies; odds ratio, 0.64; 95% confidence interval, 0.42-0.97), neonatal aspiration requiring resuscitation (19 articles, 181,001 pregnancies; odds ratio, 0.60; 95% confidence interval, 0.43-0.84), and neonatal intensive care unit admission (30 articles, 287,698 pregnancies; odds ratio, 0.56; 95% confidence interval, 0.45-0.70). CONCLUSION: When compared with land birth, water birth does not appear to increase the risk of most maternal and neonatal complications. Like any other delivery method, water birth has its unique considerations and potential risks, which health care providers and expectant parents should evaluate thoroughly. However, with proper precautions in place, water birth can be a reasonable choice for mothers and newborns, in facilities equipped to conduct water births safely.

Parturition at term: induction, second and third stages of labor, and optimal management of life-threatening complications-hemorrhage, infection, and uterine rupture.

Childbirth is a defining moment in anyone's life, and it occurs 140 million times per year. Largely a physiologic process, parturition does come with risks; one mother dies every two minutes. These deaths occur mostly among healthy women, and many are considered preventable. For each death, 20 to 30 mothers experience complications that compromise their short- and long-term health. The risk of birth extends to the newborn, and, in 2020, 2.4 million neonates died, 25% in the first day of life. Hence, intrapartum care is an important priority for society. The American Journal of Obstetrics & Gynecology has devoted two special Supplements in 2023 and 2024 to the clinical aspects of labor at term. This article describes the content of the Supplements and highlights new developments in the induction of labor (a comparison of methods, definition of failed induction, new pharmacologic agents), management of the second stage, the value of intrapartum sonography, new concepts on soft tissue dystocia, optimal care during the third stage, and common complications that account for maternal death, such as infection, hemorrhage, and uterine rupture. All articles are available to subscribers and non-subscribers and have supporting video content to enhance dissemination and improve intrapartum care. Our hope is that no mother suffers because of lack of information.

Effects of perineal massage at different stages on perineal and postpartum pelvic floor function in primiparous women: a systematic review and meta-analysis.

BACKGROUND: Perineal massage, as a preventive intervention, has been shown to reduce the risk of perineal injuries and may have a positive impact on pelvic floor function in the early postpartum period. However, there is still debate concerning the best period to apply perineal massage, which is either antenatal or in the second stage of labor, as well as its safety and effectiveness. Meta-analysis was used to evaluate the effect of implementing perineal massage in antenatal versus the second stage of labor on the prevention of perineal injuries during labor and early postpartum pelvic floor function in primiparous women. METHODS: We searched nine different electronic databases from inception to April 16, 2024. The randomized controlled trials (RCTs) we included assessed the effects of antenatal and second-stage labor perineal massage in primiparous women. All data were analyzed with Revman 5.3, Stata Statistical Software, and Risk of Bias 2 was used to assess the risk of bias. Subgroup analyses were performed based on the different periods of perineal massage. The primary outcomes were the incidence of perineal integrity and perineal injury. Secondary outcomes were perineal pain, duration of the second stage of labor, postpartum hemorrhage, urinary incontinence, fecal incontinence, and flatus incontinence. RESULTS: This review comprised a total of 10 studies that covered 1057 primigravid women. The results of the analysis showed that perineal massage during the second stage of labor reduced the perineal pain of primigravid women in the immediate postpartum period compared to the antenatal period, with a statistical value of (MD = -2.29, 95% CI [-2.53, -2.05], P < 0.001). Additionally, only the antenatal stage reported that perineal massage reduced fecal incontinence (P = 0.04) and flatus incontinence (P = 0.01) in primiparous women at three months postpartum, but had no significant effect on urinary incontinence in primiparous women at three months postpartum (P = 0.80). CONCLUSIONS: Reducing perineal injuries in primiparous women can be achieved by providing perineal massage both antenatally and during the second stage of labor. Pelvic floor function is improved in the postnatal phase by perineal massage during the antenatal stage. TRIAL REGISTRATION: CRD42023415996 (PROSPERO).

Prolonged second stage of labor in delivery using epidural analgesia is a risk factor for postpartum urinary retention.

AIM: To determine the postpartum urinary retention rate and risk factors after delivery using epidural analgesia. METHODS: This single-center retrospective study targeted 341 women who gave birth after at least 37 weeks of gestation from April to August 2021; from this cohort, 208 patients were examined. The postpartum urinary retention rate was compared between the no epidural analgesia group (n = 107) and epidural analgesia group (n = 101). Subsequently, risk factors for postpartum urinary retention were investigated in the epidural analgesia group. RESULTS: After adjustment by propensity score matching for age, body mass index, being primiparous, and labor induction as covariates, the analysis of the incidence of postpartum urinary retention revealed that the epidural analgesia group exhibited a significantly higher postpartum urinary retention rate than the no epidural analgesia group (30% vs. 11%, p = 0.02). The investigation results regarding risk factors for postpartum urinary retention in the epidural analgesia group obtained through a univariate analysis showed that being primiparous and having a prolonged second stage of labor were significantly correlated with postpartum urinary retention. Multivariate analysis indicated that a prolonged second stage of labor was an independent risk factor for postpartum urinary retention (p = 0.03; odds ratio: 3.18; 95% confidence interval: 1.08-9.77). All patients recovered from postpartum urinary retention by day 4. CONCLUSIONS: The postpartum urinary retention rate after delivery using epidural analgesia was 25.7%. In the case of epidural analgesia deliveries, a prolonged second stage of labor was an independent risk factor for postpartum urinary retention.

Correlative analysis of different treatments of persistent occipitotransverse position on the outcome for mother and infant.

OBJECTIVE: To explore the clinical feasibility of different treatment methods for persistent occipitotransverse position and the influence on maternal and infant complications. METHOD: During the trial of vaginal delivery from April 2020 to March 2023 in our hospital, the cervix was fully dilated and the presentation was located at +2 station. Ninety-six pregnant women with fetal presentation at +4 station, occipitotransverse fetal position, maternal complications, abnormalities in the second stage of labor, and or fetal distress were divided into two groups: 65 patients with Kielland forceps vaginal delivery and 31 patients underwent emergency cesarean section. The delivery time, vaginal laceration rate, postpartum blood loss volume, puerperal infection rate, neonatal birth injury rate, and neonatal 1 min Apgar scores were analyzed. RESULTS: The delivery outcomes and maternal and neonatal complications of 96 pregnant women were analyzed: the application of Kielland forceps delivery time was shorter, while the vaginal laceration rate, postpartum hemorrhage, puerperal infection rate were significantly lower than that of patients undergoing emergency cesarean section and the neonatal 1 min Apgar score was higher than that of emergency cesarean section group (p < 0.05). CONCLUSION: It was clinically appropriate to use Kielland forceps in vaginal delivery when the persistent occipitotransverse position was present and delivery needed to be expediated. Use of Kielland forceps can shorten the delivery time, improve the success rate of vaginal delivery and reduce the complications of mothers and infants.

Real-time imaging as visual biofeedback in active second stage of labor among nulliparas: a randomized controlled trial.

BACKGROUND: A prolonged second stage of labor increases the risk of severe perineal laceration, postpartum hemorrhage, operative delivery, and poor Apgar score. The second stage is longer in nulliparas. Maternal pushing during the second stage of labor is an important contributor to the involuntary expulsive force developed by uterine contraction to deliver the fetus. Preliminary data indicate that visual biofeedback during the active second stage hastens birth. OBJECTIVE: This study aimed to evaluate if visual feedback focusing on the perineum reduced the length of the active second stage of labor in comparison with the control. STUDY DESIGN: A randomized controlled trial was conducted in the University Malaya Medical Centre from December 2021 to August 2022. Nulliparous women about to commence the active second stage, at term, with singleton gestation, reassuring fetal status, and no contraindication for vaginal delivery were randomized to live viewing of the maternal introitus (intervention) or maternal face (sham/placebo control) as visual biofeedback during their pushing. A video camera Bluetooth-linked to a tablet computer display screen was used; in the intervention arm, the camera was focused on the introitus, and in the control arm, on the maternal face. Participants were instructed to watch the display screen during their pushing. The primary outcomes were the intervention-to-delivery interval and maternal satisfaction with the pushing experience assessed using a 0-to-10 visual numerical rating scale. Secondary outcomes included mode of delivery, perineal injury, delivery blood loss, birthweight, umbilical cord arterial blood pH and base excess at birth, Apgar score at 1 and 5 minutes, and neonatal intensive care unit admission. Data were analyzed with the t test, Mann-Whitney U test, chi-square test, and Fisher exact test, as appropriate. RESULTS: A total of 230 women were randomized (115 to intervention and 115 to control arm). The active second stage duration (intervention-to-delivery interval) was a median (interquartile range) of 16 (11-23) and 17 (12-31) minutes (P=.289), and maternal satisfaction with the pushing experience was 9 (8-10) and 7 (6-7) (P<.001) for the intervention and control arm, respectively. Women randomized to the intervention arm were more likely to agree to recommend their management to a friend (88/115 [76.5%] vs 39/115 [33.9%]; relative risk, 2.26 [95% confidence interval, 1.72-2.97]; P<.001) and more likely to have less severe perineal injury (P=.018). CONCLUSION: Real-time viewing of the maternal introitus as visual biofeedback during pushing resulted in higher maternal satisfaction compared with the sham control of viewing the maternal face; however, the time to delivery was not significantly shortened.

Mechanics of vaginal breech birth: Factors influencing obstetric maneuver rate, duration of active second stage of labor, and neonatal outcome.

BACKGROUND: We investigated possible parameters that could predict the need for obstetric maneuvers, the duration of the active second stage of labor (i.e., the duration of active pushing), and short-term neonatal outcome in vaginal breech births. MATERIALS AND METHODS: We performed a retrospective analysis of 268 successful singleton vaginal breech births in women without previous vaginal births from January 2015 to August 2022. Multivariable regression was used to investigate associations between maternal and fetal characteristics (including antepartum magnetic resonance (MR) pelvimetry) with obstetric maneuvers, the duration of active second stage of labor, pH values, and admission to the neonatal unit. Models for the prediction of obstetric maneuvers were built and internally validated. RESULTS: Obstetric maneuvers were performed in a total of 130 women (48.5%). A total of 32 neonates (11.9%) had to be admitted to the neonatal unit. The intertuberous distance (ITD) (p < 0.001), epidural analgesia (p < 0.001), and birthweight (p = 0.026) were associated with the duration of active second stage of labor. ITD (p = 0.028) and birthweight (p = 0.011) were also independently associated with admission to the neonatal unit, while pH values below 7.10 dropped significantly (p = 0.0034) if ITD was ≥13 cm. Furthermore, ITD (p < 0.001) and biparietal diameter (p = 0.002) were independent predictors for obstetric maneuvers. CONCLUSIONS: ITD is independently associated with the duration of active second stage of labor. Thus, it can predict suboptimal birth mechanics in the last stage of birth, which may lead to the need for obstetric maneuvers, lower arterial pH values, and admission to the neonatal unit. Consequently, MR pelvimetry gives additional information for practitioners and birthing people preferring a vaginal breech birth.

Uncertain fetal head engagement: a prospective randomized controlled trial comparing digital exam with angle of progression.

BACKGROUND: Uncertain fetal head engagement represents 4% of obstetrical situations associated with an increased risk of postpartum hemorrhage, notably in cases of cesarean delivery and increased neonatal impairment owing to failed vaginal instrumental delivery. In this obstetrical condition, cesarean delivery is recommended, but vaginal delivery is possible in two-thirds of the cases. During the second stage of labor, the descent of the fetal head can be assessed by sonography, particularly by measuring the angle of progression. OBJECTIVE: To evaluate, after a prolonged second stage of labor, the impact of measuring the angle of progression in addition to a digital examination on cesarean delivery rates when fetal head engagement remains uncertain. STUDY DESIGN: This open multicenter randomized pragmatic trial included women at term with a singleton cephalic fetus in a clinical occiput anterior position after a prolonged 2-hour second stage of labor with uncertain fetal head engagement. After inclusion in the study, an independent investigator performed ultrasound systematically to confirm the occiput anterior position and measured the angle of progression at the climax of Valsalva pushing. This operator did not participate in labor management. In the study group but not in the control group, the angle of progression was communicated to the obstetrician in charge of labor management. Obstetricians were encouraged to attempt vaginal birth if the angle of progression was >120°. The primary outcome was the cesarean delivery rate. Secondary outcomes were operative delivery rate (cesarean delivery and operative vaginal delivery), maternal complications (third and fourth-degree perineal tears, failed vaginal instrumental delivery, postpartum hemorrhage, hysterectomy), and neonatal outcomes (Apgar score <5 at 10 minutes, umbilical arterial pH <7.10, neonatal wounds, neonatal intensive care unit admission). RESULTS: A total of 45 women were included in the study. Occiput anterior position was confirmed in 33 women: 16 in the study group and 17 in the control group. Women's characteristics at baseline were similar between the groups. The median (range) angles of progression were similar: 138.4° (15) and 140.3° (16.9) in the study and control group, respectively. Cesarean delivery rates were 12.5% in the study group and 41.1% in the control group (P=.06). Secondary outcomes were similar between the 2 groups. No failed vaginal instrumental delivery was reported. CONCLUSION: Measurement of the angle of progression in addition to digital examination when fetal head engagement remained uncertain showed promising results in decreasing cesarean delivery rates. A larger multicenter randomized controlled trial is needed to confirm these results.

On the management of maternal pushing during the second stage of labor: a biomechanical study considering passive tissue fatigue damage accumulation.

BACKGROUND: During the second stage of labor, the maternal pelvic floor muscles undergo repetitive stretch loading as uterine contractions and strenuous maternal pushes combined to expel the fetus, and it is not uncommon that these muscles sustain a partial or complete rupture. It has recently been demonstrated that soft tissues, including the anterior cruciate ligament and connective tissue in sheep pelvic floor muscle, can accumulate damage under repetitive physiological (submaximal) loads. It is well known to material scientists that this damage accumulation can not only decrease tissue resistance to stretch but also result in a partial or complete structural failure. Thus, we wondered whether certain maternal pushing patterns (in terms of frequency and duration of each push) could increase the risk of excessive damage accumulation in the pelvic floor tissue, thereby inadvertently contributing to the development of pelvic floor muscle injury. OBJECTIVE: This study aimed to determine which labor management practices (spontaneous vs directed pushing) are less prone to accumulate damage in the pelvic floor muscles during the second stage of labor and find the optimum approach in terms of minimizing the risk of pelvic floor muscle injury. STUDY DESIGN: We developed a biomechanical model for the expulsive phase of the second stage of labor that includes the ability to measure the damage accumulation because of repetitive physiological submaximal loads. We performed 4 simulations of the second stage of labor, reflecting a directed pushing technique and 3 alternatives for spontaneous pushing. RESULTS: The finite element model predicted that the origin of the pubovisceral muscle accumulates the most damage and so it is the most likely place for a tear to develop. This result was independent of the pushing pattern. Performing 3 maternal pushes per contraction, with each push lasting 5 seconds, caused less damage and seemed the best approach. The directed pushing technique (3 pushes per contraction, with each push lasting 10 seconds) did not reduce the duration of the second stage of labor and caused higher damage accumulation. CONCLUSION: The frequency and duration of the maternal pushes influenced the damage accumulation in the passive tissues of the pelvic floor muscles, indicating that it can influence the prevalence of pelvic floor muscle injuries. Our results suggested that the maternal pushes should not last longer than 5 seconds and that the duration of active pushing is a better measurement than the total duration of the second stage of labor. Hopefully, this research will help to shed new light on the best practices needed to improve the experience of labor for women.

Manual rotation of occiput posterior or transverse positions: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: The primary objective of this systematic review was to assess the association between spontaneous vaginal delivery and manual rotation during labor for occiput posterior or transverse positions. Our secondary objective was to assess maternal and neonatal outcomes. DATA SOURCES: An electronic search of PubMed, EMBASE, ClinicalTrials.gov, and the Cochrane Register of Controlled Trials covered the period from January 2000 to September 2021, without language restrictions. STUDY ELIGIBILITY CRITERIA: The eligibility criteria included all randomized trials with singleton pregnancies at ≥37 weeks of gestation comparing the manual rotation groups with the control groups. The primary outcome was the rate of spontaneous vaginal delivery. Additional secondary outcomes were rate of occiput posterior position at delivery, operative vaginal delivery, cesarean delivery, postpartum hemorrhage, obstetrical anal sphincter injury, prolonged second stage of labor, shoulder dystocia, neonatal acidosis, and phototherapy. Subgroup analyses were performed according to types of position (occiput posterior or occiput transverse), techniques used (whole-hand or digital rotation), and parity (nulliparous or parous). METHODS: The quality of each study was evaluated with the revised Cochrane risk-of-bias tool for randomized trials, known as RoB 2. The meta-analysis used random-effects models depending on their heterogeneity, and risks ratios were calculated for dichotomous outcomes. RESULTS: Here, 7 of 384 studies met the inclusion criteria and were selected. They included 1402 women: 704 in the manual rotation groups and 698 in the control groups. Manual rotation was associated with a higher rate of spontaneous vaginal delivery: 64.9% vs 59.5% (risk ratio, 1.09; 95% confidence interval, 1.03-1.16; P=.005; 95% prediction interval, 0.90-1.32). This association was no longer significant after stratification by parity or technique used. Manual rotation was associated with spontaneous vaginal delivery only for the occiput posterior position (risk ratio, 1.08; 95% confidence interval, 1.01-1.15). Furthermore, it was associated with a reduction in occiput posterior or transverse positions at delivery (risk ratio, 0.64; 95% confidence interval, 0.48-0.87) and episiotomies (risk ratio, 0.84; 95% confidence interval, 0.71-0.98). The groups did not differ significantly for cesarean deliveries, operative vaginal deliveries, or neonatal outcomes. CONCLUSION: Manual rotation increased the rate of spontaneous vaginal delivery.

Effect of prolonged second stage of labor on pelvic floor function: A prospective cohort study.

INTRODUCTION AND HYPOTHESIS: To evaluate the effect of the second stage of labor (SSL) lasting > 2 h on pelvic floor function. METHODS: This single-center prospective cohort study included primiparous women with SSL > 2 h treated at Tongji Hospital between January 2018 and December 2019 (case group). A matched group of women with similar newborn weight and SSL < 2 h were recruited simultaneously (control group). Stress urinary incontinence (SUI) and pelvic floor muscle (PFM) characteristics were measured at 6 weeks, 6 months, and finally 1 year postpartum. RESULTS: A total of 63 pairs of primiparous women completed 1-year follow-up. The incidence of SUI in the case group was significantly higher than that in the control group at 6 weeks postpartum (P = 0.020); however, the differences were not significant at 1 year postpartum (P=1.00). PFM endurance was significantly lower in the case group at 6 weeks (P = 0.000), 6 months (P = 0.000), and 1 year (P = 0.011) after childbirth. There was no difference in PFM strength between the two groups. The maximal voluntary contraction (MVC) of PFM was significantly lower in the case group at 6 weeks postpartum (P = 0.007), but the differences were not significant at 1 year postpartum (P = 0.197). PFM endurance and MVC were higher at 1 year than at 6 weeks postpartum in both groups. CONCLUSIONS: The SSL > 2 h increased the incidence of SUI at 6 weeks postpartum and decreased PFM endurance for 1 year.

The mediating effect of the prolonged second stage of labor on delivery mode and urinary incontinence among postpartum women: evidence from Shandong, China.

INTRODUCTION AND HYPOTHESIS: This study was aimed at exploring the mediating role of the prolonged second stage of labor (PSSL) in the association between delivery mode and urinary incontinence (UI) among postpartum women in Shandong, China. METHODS: A cross-sectional study involving postnatal women from the Women's Pelvic Floor Functional Health Center in Shandong, China, was conducted. An electronic questionnaire was used to collect the data between June 2020 and February 2021. UI was assessed using the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI SF). Logistic regression and multiple linear regression were employed to explore the association among delivery mode, PSSL, and UI, and the mediating role of PSSL. RESULTS: Among the total of 5,586 postpartum women included in this study, the prevalence of UI was 13.3%. Among the 742 patients with UI, the prevalence of stress urinary incontinence (78.3%) was greater than urge urinary incontinence (8.6%), mixed urinary incontinence (9.3%), and others (3.8%). After adjusting for controlling variables, delivery mode was found to be significantly associated with PSSL, whereby women with vaginal delivery were more likely to be in PSSL, and women with PSSL had a higher probability of suffering from UI. PSSL played a partial mediating effect in delivery mode and UI. CONCLUSIONS: This study provided evidence that the effect of delivery mode on UI was partially mediated by PSSL among postpartum women in Shandong, China. Strategies to prevent PSSL should be actively adopted to reduce the risk of UI in women.

Postpartum urinary incontinence and birth outcomes as a result of the pushing technique: a systematic review and meta-analysis.

INTRODUCTION AND HYPOTHESIS: Directed pushing while using the Valsalva maneuver is shown to lead to bladder neck descent, especially in women with urinary incontinence (UI). There is insufficient evidence about the benefits or adverse effects between the pushing technique during the second stage of labor and urinary incontinence postpartum. The objective of this study was to evaluate the effects of the pushing technique for women during labor on postpartum UI and birth outcomes. METHODS: Scientific databases were searched for studies relating to postpartum urinary incontinence and birth outcomes when the pushing technique was used from 1986 until 2020. RCTs that assessed healthy primiparas who used the pushing technique in the second stage of labor were included. In accordance with Cochrane Handbook guidelines, risk of bias was assessed and meta-analyzed. Certainty of evidence was assessed using the GRADE approach. RESULTS: Seventeen RCTs (4606 primiparas) were included. The change in UI scores from baseline to postpartum was significantly lower as a result of spontaneous pushing (two studies; 867 primiparas; standardized mean difference: SMD -0.18, 95% CI -0.31 to -0.04). Although women were in the recumbent position during the second stage, directed pushing group showed a significantly shorter labor by 21.39 min compared with the spontaneous pushing group: there was no significant difference in the duration of the second stage of labor between groups. CONCLUSIONS: Primiparas who were in the upright position and who experienced spontaneous pushing during the second stage of labor could reduce their UI score from baseline to postpartum.

Association between the second-stage duration of labor and perinatal outcomes in women with a prior cesarean delivery.

BACKGROUND: The cesarean delivery (CD) rate has been increasing globally. Trial of labor after cesarean delivery (TOLAC) has been used as a key method for the reduction of the CD rate. Little is known, however, about the association between the second-stage duration of TOLAC and adverse maternal and neonatal outcomes. This study evaluated the association between perinatal outcomes and the duration of second-stage labor in women undergoing TOLAC. METHODS: A 10-year retrospective cohort study was performed at the Department of Obstetrics and Gynecology, Third Affiliated Hospital of Guangzhou Medical University, between January 2010 and January 2020. Women undergoing TOLAC who reached the second stage of labor were included in this study. Duration of the second stage of labor was examined as a categorical variable (group I: <0.5 h, group II: 0.5-2 h and group III: ≥2 h) and as a continuous variable to evaluate the association with adverse perinatal outcomes by using multivariable regression models and a Cox proportional hazards regression model adjusting for potential confounders. RESULTS: Of the 1,174 women who met the inclusion criteria, the median (interquartile range) length of the second stage was 0.5 h (0.3-0.9 h). Among them, 1,143 (97.4%) delivered vaginally and 31 underwent an unplanned CD. As the second-stage duration increased, operative vaginal delivery (OVD), CD, and postpartum hemorrhage (PPH) rates increased. Women in group III had higher risks of OVD (aOR = 11.34; 95% CI [5.06-25.41]), CD (aOR = 4.22; 95% CI [1.32-13.43]), and PPH (aOR = 2.43; 95% CI [1.31-4.50]) compared with group I. Correspondingly, blood loss and the oxytocin used to treat PPH increased significantly, while the postpartum hemoglobin reduced significantly in group III compared with group I. The incidence of uterine rupture, uterine atony, cervical laceration, red blood cell transfusion, and intensive care unit admission were similar in all three groups. Neonatal outcomes were not affected by the second-stage duration. CONCLUSIONS: Women undergoing TOLAC with second-stage duration of ≥2 h have higher odds of OVD, unplanned intrapartum CD, and PPH.

An extremely prolonged second stage of labor increases maternal complications but has no adverse effect on neonatal outcomes.

AIM: To investigate how an extremely prolonged second stage of labor of 12 h or more affects maternal and neonatal outcomes. MATERIAL AND METHODS: This retrospective cohort study included nulliparous, pregnant women with 37 + 0 to 41 + 6 weeks of gestation whom vaginal delivery was attempted at the Yokohama City University Medical Center between 2014 and 2018. RESULTS: In 446 cases of the prolonged second stage of labor, there were 296 women (66%) in the 2- to 6-h second stage of labor group, 112 women (25%) in the 6- to 12-h group, and 38 women (8.5%) in the 12-h or longer group. The longer the second stage of labor, the more significant was the increase in the rates of augmentation of the delivery, emergency cesarean delivery, and operative vaginal delivery. Even in the 12 h or longer group, 82% were able to have vaginal delivery. The 6- to 12-h group had a significant increase in third- or fourth-degree perineal lacerations compared to the 2- to 6-h group (aOR 8.12 [95% CI 1.55-42.6]). Clinical chorioamnionitis was significantly increased in the 12 h or longer group (aOR 4.88 [95% CI 1.62-14.8]). In terms of neonatal outcomes, comparison between the three groups showed no significant difference. CONCLUSION: With an extremely prolonged second stage of labor, maternal complications involved a significant increase in severe perineal lacerations and chorioamnionitis; however, there was no increase in adverse outcomes for neonates. It was not possible to conclusively determine if the duration of the second stage is acceptable.

Outcomes of the novel Odon Device in indicated operative vaginal birth.

BACKGROUND: No new method of assisting vaginal birth has been introduced into clinical practice since the development of the vacuum extractor in the 1950s. The Odon Device is a new device that employs a circumferential air cuff over the fetal head to assist birth. In this study, the Odon Device has been used to assist vaginal birth for standard clinical indications. OBJECTIVE: This study aimed to investigate the clinical impact, safety, and acceptability of the Odon Device to women, their babies, and clinicians and to assess the feasibility of recruiting women to an interventional intrapartum research study. STUDY DESIGN: This is a nonrandomized, single-arm interventional feasibility study of the Odon Device for operative vaginal birth undertaken in a single maternity unit: Southmead Hospital, Bristol, United Kingdom. The Odon Device was used to assist birth in 40 women who required the birth to be assisted for suspected fetal compromise and/or prolonged second stage of labor. The primary clinical outcome was the proportion of births successfully assisted with the Odon Device, and the primary feasibility outcome was the proportion of eligible women who were approached and who agreed to participate. Neonatal outcome data were reviewed at day 28, and maternal outcomes were investigated up to day 90. RESULTS: Between October 2018 and January 2019, 298 of 384 approached, eligible women (77.6%) consented to participate. Of these women, 40 received the intervention-the use of the Odon Device. Birth was assisted in all cephalic (occiput anterior, occiput transverse, and occiput posterior) fetal positions, at all stations at or below the ischial spine and with or without regional analgesia. The Odon Device was effective in 19 of 40 cases (48%). Of the 40 births, 21 (52.5%) required additional assistance: 18 of 40 births (45%) were completed using nonrotational forceps, 1 of 40 births (3%) required rotational forceps, and 2 of 40 births (5%) required an emergency cesarean delivery. There was no serious maternal or neonatal adverse event related to the use of the device, and there was no serious adverse device effect. There were 4 devices (10%) that were ineffective because of a manufacturing fault. Furthermore, 39 of 40 women (98%) reported a high birth perception score. All practitioners were able to use the device as intended, although some steps in using the device were reported to be easier to perform (setup and deflation of air chamber) than others (application of the device and withdrawal of the applicator). CONCLUSION: Recruitment to an interventional study of a new device for operative vaginal birth was feasible; 78% of eligible women were willing to participate, often expressing an aspiration for an alternative to forceps and vacuum. The success rate of the Odon Device was lower than reported success rates of vacuum and forceps; however, in this study, the device had been used to assist birth for standard clinical indications. There was no significant maternal or neonatal safety concern associated with the use of the device, although the number of births studied was small. Further feasibility study to establish iterative changes to the device, technique, and clinical indications is necessary.